'Star Wars' Sarlacc's Mouth Found on Prehistoric Worm

A 520-million-year-old fossilized mouth of unknown body has long been a mystery, but fresh evidence shows that it not only belonged to a 3.3-foot-long voracious predator, but it was also nearly identical to the mouth of carnivorous Sarlacc from the Star Wars film "Return of the Jedi."

The discovery, reported in the journal Palaeontology, sheds light on the very ancient creature Pambdelurion whittingtoni, which was a primitive relative of today's insects, spiders and crustaceans -- collectively known as arthropods.

Jakob Vinther of Bristol University and his team describe Pambdelurion as looking like a gigantic worm with 12 stubby legs, matching sets of flaps running down its body, and a circular mouth with several rows of teeth.

"The mouth is a spitting image of the Sarlacc from Star Wars," Vinther said in a press release, referring to the movie beast with its gaping mouth in the sand dunes of Tatooine.

Vinther and his team conducted a series of expeditions in North Greenland. There they found fossils of Pambdelurion that helped to solve many questions about the mysterious mouth.

At first paleontologists thought that the mouth belonged to Anomalocaris, the largest sea predator from the Cambrian Period. They also thought the mouth was comparable to that of the penis worm, a spiny marine predator that looks like its namesake.

The new evidence "solves a mystery for the affinities of this giant mouth and demonstrates that the two previous hypotheses -- whether the mouth belongs to Anomalocaris or a penis worm -- are not exactly right, but not entirely wrong either," Vinther said.

Added to the mix is another prehistoric creature called Omnidens that had a similar mouth to Pambdelurion.

The scientists analyzed the remains of both Omnidens and Pambdelurion and determined that they lived on the seafloor. They and existing arthropods are closely related to roundworms, horsehair worms, mud dragons and penis worms.

Photo: Fossil of Pambdelurion from North Greenland. Credit: Fletcher Young

"What we see in these arthropod ancestors is the same kind of mouth as in penis worms -- right down to details of the rings of teeth and plates -- and we argue that this was present in the last common ancestor," co-author Greg Edgecombe from the Natural History Museum said.

During Pambdelurion and Omnidens' lifetime there was an escalation in species diversity driven by increases in oxygen that, in turn, led to the origin of predation. The latter drove the emergence of more active creatures and the ingestion by some of large quantities of food.

"It seems as if nowhere was safe back in the Cambrian," said co-author Fletcher Young, a former Bristol masters student. "No matter whether you lived in the water column or on the seafloor there was a big, ugly beast that would devour you."

Predators such as Pambdelurion and its kind were organisms that helped to fuel the Cambrian explosion of life that has impacted our planet ever since.

As for the sarlacc (usually referred to in lower case), the Star Wars Databank says the creature defies taxonomic classification.